The majority of US adolescents aged 12-18 have regular access to the internet and a significant portion engage in High-risk Internet Behaviors (HRIBs) including online exposure to sexually explicit content and engaging in online social behaviors that could lead to internet-initiated victimization. Current internet safety programs rel heavily on parental monitoring as a primary means of protecting teens yet over 40% of teen internet users report unwanted exposure to sexual content with another 20% admitting to intentionally seeking online pornographic materials. Moreover, an increasing number of parents allow their kids to over-report their age in order to be granted access to social networking sites-places where risky online social behaviors such as divulging personal identifying information and posting sexually provocative self-descriptors increase vulnerability for online exploitation, and where most internet-initiated sex crimes originate. Extant internet safety studies are highly criticized for reliance on adolescent self-reports. Hence, there is limited objective knowledge about the magnitude and impact of HRIBs and, of equal importance, which teens might be the most susceptible. Our research shows that sexually abused adolescents may be especially vulnerable to HRIBs because these victims demonstrate a greater propensity toward pornography consumption, provocative online self-presentations, online sexual advances, offline meetings, risky sexual behaviors and sexual re-victimization than do their non-abused peers. Our multidisciplinary team will conduct a naturalistic study of 400 adolescent females aged 12-15; half of whom recently experienced substantiated sexual abuse. The study will be the first to go beyond adolescent self-reports of HRIBs via (1) assessing adolescents' internet footprints by recording all URL activity within a 4-week period and quantifying URLs for adult and sexual content, and (2) objectively quantifying HRIBs both online and in-vivo in the lab. These procedures, along with a comprehensive psychosocial interview, will be repeated every 15 months for 2 subsequent time points in an accelerated longitudinal, cross-sequential design allowing for cross-lag and developmental modeling across adolescence from age 12-18. The overall objective is to fully inform teen internet safety campaigns by providing objective HRIBs prevalence rates and articulating their impact on adolescent development. By focusing on the high-risk group of sexually abused adolescents and testing a conceptual model which includes a comprehensive set of risk and protective factors, findings will not only enhance treatment models for abuse victims, but will orient parents and policy makers about the best ways to promote internet safety for teens in general. This innovative research will fill important gaps in school-based internet safety programs by highlighting the implications for provocative self-presentations and recommending ways to protect teens whose parents are not internet savvy or are otherwise uninvolved. Results will enhance secondary prevention and intervention efforts by identifying potent, adolescent, family and contextual variables that serve to curtail the impact of HRIBs once they occur.